DESCRIPTION (provided by investigator): As recent events have demonstrated, Bacillus anthracis can and has been used as a weapon of bioterrorism. The detection, tracking, and interdiction of various Bacillus anthracis strains is therefore of great concern, as is the treatment of anthrax infection, in order to generate molecular tools that can serve as resources in all of these venues, we propose to select nucleic acid binding species (aptamers) against the proteomes of one of the virulence plasmids associated with Bacillus anthracis, pXO1. These experiments will serve as a starting point for the immediate development of biosensors capable of identifying Bacillus anthracis, and will set the stage for future efforts in tracking, interdiction, and therapy. In particular, we plan to: 1. Increase the throughput of automated selection experiments. 2. Select aptamers against the pXO1 proteome. 3. Develop informatics methods for designing signaling aptamers. Overall, the significance of the proposed work can be succinctly summarized as follows: there are, no real-time or continuous methods for the detection of B. anthracis, primarily because there are no biopolymer reagents that can report molecular interactions without the need of immobilization or other processing steps (e.g., PCR, ELISA). The signaling aptamers we propose to develop will be unique in this respect. In addition, aptamers have a therapeutic potential that rivals that of monoclonal antibody or other protein drugs (see, for example, B.3). Therefore, we believe that the reagents developed during the execution of this application will be of great use to the entire biodefense community, and that investment in this work will have a significant multiplier effect. As a single example, based on our previous interactions with the military, we are poised to send any aptamers that are produced directly to the Critical Reagents Program of the Joint Program Office for Biotogicat Defense (JPOBD) for further assay and adaptation to military sensor systems.